FOOD/DRINK [I, T] › to give someone food or drink, especially guests or customers in a restaurant or bar: We're not allowed to serve alcohol to anyone under 18. SHOP [I, T] › to help customers and sell things to them in a shop: Are you being served? WORK [I, T] › to do work that helps society, for example in an organization such as the army or the government: to serve in the army to serve on a committee/jury He served as mayor for 5 years. BE USEFUL [I, T] › to be useful as something: It's a very entertaining film but it also serves an educational purpose. The spare bedroom also serves as a study. [+ to do sth] He hopes his son's death will serve to warn others about the dangers of owning a gun. PRISON [T] › to be in prison for a period of time: Williams, 42, is serving a four-year jail sentence. SPORT [I] › in a sport such as tennis, to throw the ball up into the air and then hit it towards the other player serves one/two/four, etc › If an amount of food serves a particular number, it is enough for that number of people. → See also It serves her/him/you right!